1. Field of the Invention
The present invention relates to devices for feeding flowable raw material to production machines, and more particularly to devices for feeding synthetic plastic material in granular or pulverulent form to injection molding machines at a rate which automatically adjusts itself to the production rate of the injection molding machine.
2. Description of the Prior Art
The prior art in this field includes a known feeding device in which the desired level of material awaiting entry into the plastification unit is maintained automatically by means of electro-mechanical controls which include a rocking lever on a horizontal pivot shaft. One end of the lever is positioned underneath the intake opening of the raw material supply line, while the other end of the lever carries a counter-weight which also serves to electrically control the start and stop of a pneumatic air conveyance system which moves the raw material from a storage receptacle to the plastification unit of the injection molding machine. such a device is disclosed in the German Auslegeschrift (Publ. Allowed Appln.) No. 1,729,523.